fix: make secret redaction one-way and fail closed - #1

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CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

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@datj9

@datj9datj9 commented Jul 18, 2026

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What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
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What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix"); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
Copy Markdown

What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms"); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
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What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links"); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
Copy Markdown

What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default"); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
Copy Markdown

What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers"); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

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What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode"); } } catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); } })(); })();
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fix: make secret redaction one-way and fail closed - #1

Open
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction
Open

fix: make secret redaction one-way and fail closed#1
datj9 wants to merge 1 commit into
CommandOSSLabs:mainfrom
datj9:security/one-way-secret-redaction

Conversation

@datj9

@datj9datj9 commented Jul 18, 2026

Copy link
Copy Markdown

What this improves

This PR turns dotmask from reversible response rewriting into one-way, fail-closed request redaction. It addresses the security review findings as follows.

AreaBeforeImproved behavior
Response secret oracleFake tokens in model responses and tool calls were replaced with real secrets locally. A model could request encoding or exfiltration of the restored value.Provider responses are forwarded byte-for-byte. All response-unmasking code and tests are removed, so model-controlled output cannot resolve a fake into a real secret.
Request coverageOnly selected fields in parseable JSON POST bodies were scanned. Generic nested properties, textual bodies, GET bodies, encoded output, and malformed JSON could bypass masking.Every JSON string leaf is traversed recursively. Supported textual bodies and standalone high-entropy values are scanned. Body sanitization applies regardless of HTTP method.
Fail-open behaviorNon-JSON, malformed, compressed, and unsupported bodies could be forwarded without inspection.Intercepted requests fail closed when JSON is malformed or when the body is compressed, binary, or unsupported.
Fake-token predictabilityFakes used an unkeyed deterministic 32-bit seed and unknown formats leaked a plaintext prefix.Fakes use a random process-local HMAC key. Unknown formats expose no plaintext prefix, while known structural prefixes and lengths remain compatible.
Secret persistenceReal-to-fake mappings were stored in Keychain, fake identifiers were written to disk, and real values were retained in a process-wide cache.Mappings are request-local only. The proxy performs no Keychain writes and persists no real-secret mappings.
CA trust scopeThe generated CA was installed as a trusted root in the login Keychain.Claude Code trusts the CA only through NODE_EXTRA_CA_CERTS. Installation removes legacy broad CA trust when found.
Uninstall safetyCleanup errors were swallowed and certificates, mappings, Keychain items, and logs could remain after a successful-looking uninstall.Daemon and CA cleanup failures are reported. Uninstall removes identifiable legacy Keychain mappings and deletes certificates, mappings, logs, and managed settings after successful cleanup.
HTTP parser hardeningRequest framing had no size bounds and accepted ambiguous or duplicate critical headers.Requests have 64 KiB header and 16 MiB body limits. Duplicate headers, conflicting Content-Length and Transfer-Encoding, invalid lengths, and unsupported transfer encodings are rejected.
DocumentationThe project claimed that secrets never leave the machine and documented transparent restoration.README, architecture, security policy, CLI text, and package metadata now describe the actual defense-in-depth scope and limitations.

Security impact

The most important change closes the response-side secret oracle. Previously, a model that received a fake token could place it in a shell command such as an encoding or network command. Dotmask would restore the real value before local execution, allowing the model or another endpoint to receive it. Version 2 never materializes real secrets from provider-controlled responses.

The proxy now also blocks intercepted request formats it cannot safely inspect instead of forwarding them unchanged.

Breaking change

This is intentionally versioned as 2.0.0. Model-generated commands containing fake credentials no longer become usable credentials automatically. Tools must obtain real credentials from a trusted local environment at execution time.

Dotmask remains defense in depth rather than a sandbox or DLP boundary. Provider authentication headers still reach the provider, non-allowlisted hosts are passed through, and agents with local filesystem or shell permission must still be constrained with approvals, sandboxing, least-privilege credentials, and network controls.

Verification

  • npm test: 95 passing
  • TypeScript build: passing
  • npm audit: 0 vulnerabilities
  • npm pack --dry-run: expected runtime files only
  • git diff --check: clean

@datj9
datj9force-pushed the security/one-way-secret-redaction branch from c42b426 to ce52915CompareJuly 18, 2026 05:04
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@datj9